Clear WiMax: Bandwidth Throttling Now In-Place?

A few months ago, I decided to try out Clear Wireless WiMax as they offer ‘unlimited’ 6Mbs down over WiMax (refer to Clear WiMax in Atlanta, Clear WiMax Intial Review, and Clear WiMax Follow-up). However, after a few weeks, I started receiving notices that I was using too much bandwidth (see Clear ‘Unlimited’ Plans and Clear Usage Addendum).

More recently these warning letters have ceased with no explanation.

A few notes about WiMax; it is a very moody connection: often I can get speeds of up to 8Mbps, but other times I am stuck at around 2Mbps (rotating the router an inch or so left/right usually resolves this). During a rainstorm, my speed tops out at about 3Mbps, but with a wide range of variance (4Mbs down to 500kbps). The result of this bandwidth ‘feature’ it is very often hard to figure out what the heck is going on.

Today I tweaked with my bandwidth monitor (NetLimiter) to try to see if there are any traffic shaping/throttling patterns.

  • One obvious pattern is that if I use my full bandwidth for 10 minutes, by speed drops to 1Mbps (about 125kB/sec). If I disconnect for about 15 minutes and reconnect, the bandwidth returns to full speed.
  • If I run full speed for 9 minutes, cap my downloads to 1Mbps for 9 minutes and then go back to full speed, I will top out at about 1.9Mbps and 10 minutes later it drops to 1Mbps.
  • When I set my download limit to about 3.6Mbps (450kB/sec), I do not see any throttling after 25 minutes at this speed.
  • After about 9pm at night, there does not appear to be any bandwidth throttling

It could be my imagination or it could be an incredible coincidence, but I believe that Clear Wireless is doing bandwidth throttling in the Atlanta, GA area. While I am not overly concerned as I am using WiMax as a secondary connection, it would be very nice to know the stipulations of this traffic shaping if this actually being enforced!

Update: It also appears that this is only being used during peak hours- and the 'peak hours' are not always the same. Yesterday (Sunday), there did not appear to be a cap in place until around 5pm. This limited me to 1Mbps if I used any amount of bandwidth for over 10 minutes. It ended around 11:00pm. Perhaps this is an automated system that starts limiting connections when a WiMax tower is being saturated?

Update 2: Pretty much the same as before; bandwidth caps occur between 5pm to 11pm and not on Sunday- but I noticed that the caps are at different levels on different occasions; sometimes 1Mbps, others 2Mbps, etc. This does appear to be some sort of 'auto throtting' that kicks in- perhaps when the WiMax tower is saturated?

Another interesting note is that rebooting the modem usually clears the limit (until the 10 minute timeout expires); so I would guess the cap is per session and not per device (and rebooting establishes a new session)?


Firefox Fixes

I started using OpenDNS again -after not being overly excited with the Google public DNS results- and I am back to the annoying OpenDNS ‘guide’ results when I enter keywords into the address bar of Firefox (instead of the keywords being submitted as a Google search). I did a little searching and found that there is a setting to fix this:

  • In the Firefox address bar, type 'about:config’ and press enter.
  • Accept the ‘I’ll Be Careful: I Promise’ prompt
  • Search for ‘keyword.URL’.
  • Modify the entry for ‘keyword.URL’ to be:

After this is done, multi-word searches in the address bar will now be sent to Google. (Single word searches will still default to the OpenDNS guide.)

Firefox also slows down over time (much like Windows). I found a freeware program SpeedyFox from Crystalidea that will optimize the Firefox sql database and allow it to run a little better.